Fast synchronization for half duplex digital communications

Abstract

Half duplex, Frequency Hopped-Spread Spectrum wireless transceivers (102), operating without a central controller, maintain time synchronization with the frequency hopping sequence for a period after transmission of a half duplex signal ceases. The wireless transceiver (102) operates their receivers (308) according to the RF frequency hopping sequence and schedule (200). The wireless transceiver (102) is then able to send a short transmission request to signal that it will start transmitting on the Frequency Hopping schedule (200) of the previously ceased transmission. A wireless transceiver (102) that was either the original transmitter or the original receiver is able to transmit this transmission request. A subset of time slots within the hopping schedule (200) can be optionally assigned to the original transmitter and original receiver to obviate collisions of the transmit request transmissions from both device at the same time.

Description

FIELD OF THE INVENTION[0001]The present invention generally relates to the field of wireless communications and more particularly to transmission synchronization between and / or among wireless transceivers.BACKGROUND OF THE INVENTION[0002]Minimizing the design complexity of wireless transceivers, such as portable telephones and “walkie-talkies,” reduces costs and often decreases weight and power consumption. Reducing cost, weight and power consumption of these devices is advantageous for all types of devices, particularly for portable communications equipment. Wireless transceivers sometimes use a half duplex mode of communications where only one wireless transceiver transmits at a time. When the one wireless transceiver transmits, one or more other wireless transceivers receive this signal.[0003]Many wireless transceivers utilize communications protocols that incorporate a pre-defined time frame. In order for these devices to communicate, two or more devices communicating with such ...

AI Technical Summary

Problems solved by technology

Minimizing the design complexity of wireless transceivers, such as portable telephones and “walkie-talkies,” reduces costs and often decreases weight and power consumption.

This standard signal, however, requires an allocation of transmission bandwidth and limits the flexibility of communications between and / or among remote radio equipment.

This synchronization processing is often consumes time and power and is therefore ill-suited to half-duplex communications system where the transmitting wireless transceiver frequently alternates among the wireless transceivers used for point-to-point communications.

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